1. Field of the Invention
The invention relates to a stereoscopic display technique for a liquid crystal display device, more particularly to a stereoscopic display technique that can be used to produce stereoscopic effects by modifying polarizers of a liquid crystal display device.
2. Description of the Related Art
In order to enable a flat screen to present a stereoscopic effect, the principle of stereoscopic vision has to be employed. In other words, an image intended to be seen with the left eye should be transmitted to the left eye, and an image intended to be seen with the right eye should be transmitted to the right eye so that, after processing by the brain, stereoscopic images will be formed in the brain.
For three-dimensional motion pictures, they can be produced using the principle of polarization imaging, i.e., using two cameras to capture left and right eye images from two slightly different angles, and respectively subjecting the left and right images to horizontal polarization processing and vertical polarization processing before they are projected onto a screen. A viewer intending to see the stereoscopic movie needs to wear stereoscopic glasses. The left lens in the stereoscopic glasses is a horizontally polarized lens, and the right lens in the stereoscopic glasses is a vertically polarized lens. When light passes through the two polarized lenses, since the polarized lenses filter out light of different polarization directions and permit passage of similarly polarized light only, the horizontally polarized left eye image can only pass through the horizontally polarized lens, and the vertically polarized right eye image can only pass through the vertically polarized lens, so that the left eye image is presented to the left eye of the viewer and the right eye image is presented to the right eye of the viewer, thereby resulting in a visually stereoscopic effect.
To produce a stereoscopic effect on a liquid crystal display, the working principle is similar to that described in connection with the making of three-dimensional motion pictures. A conventional stereoscopic display system 9 is shown in FIG. 1. The system 9 includes a liquid crystal screen 90, a micro retardation film 91 attached to the liquid crystal screen 90, and stereoscopic glasses 92. The liquid crystal screen 90 receives a left eye image signal 901 and a right eye image signal 902, displays the left eye image signal 901 in odd-number rows of pixels, and displays the right eye image signal 902 in even-number rows of pixels. The micro retardation film 91 has a plurality of interlaced horizontal first and second phase delay regions 911, 912. A difference in phase delay between the first phase delay region 911 and the second phase delay region 912 is one half of a wavelength. In addition, the first phase delay regions 911 correspond in position to the odd-number pixel rows of the liquid crystal screen 90, whereas the second phase delay regions 912 correspond in position to the even-number pixel rows.
On the other hand, a left eye lens 921 of the stereoscopic glasses 92 is designed to permit passage of light passing through the first phase delay regions 911, whereas a right eye lens 922 is designed to permit passage of light passing through the second phase delay regions 912. Thus, the left eye image signal 901 is sent from the odd-number pixel rows through the first phase delay regions 911 of the micro retardation film 91 and further through the left eye lens 921 so as to be received by the left eye, and the right eye image signal 902 is sent from the even-number pixel rows through the second phase delay regions 912 of the micro retardation film 91 and further through the right eye lens 922 so as to be received by the right eye, thereby enabling the viewer to view stereoscopic images.
However, since the conventional stereoscopic display system 9 utilizes the liquid crystal screen 90 that has the micro phase retardation film 91 additionally attached thereto in order to produce a stereoscopic display effect in conjunction with the use of the stereoscopic glasses 92, the manufacture of the stereoscopic display system 9, in comparison with the manufacture of a conventional liquid crystal display screen without the micro phase retardation film 91, requires addition or change of processing steps and adjustment of production line equipment, thereby resulting in increased manufacturing costs and inconvenience.